color safe

[News]

Is it true that there is a limited number of colors that can be rendered on
the internet?

If this is true, where can I go to learn about it?

Will the colors in an image be altered if the colors are not the correct
hue?

Thanks

 

[Jonathan N. Little]

Is it true that there is a limited number of colors that can be rendered on
the internet?

If this is true, where can I go to learn about it?

Will the colors in an image be altered if the colors are not the correct
hue?

Maybe back it the days of 8-bit video cards, however you have no control
over whether your visitors have their monitor's adjusted properly and
color calibrated.

 

[Jim Higson]

Is it true that there is a limited number of colors that can be rendered
on the internet?

If this is true, where can I go to learn about it?

Will the colors in an image be altered if the colors are not the correct
hue?

There is a semi-official 'web safe' palette, but these days pretty much all
palettes are web safe so I wouldn't bother. Besides, the few computers that
still reduce the colours won't look all *that* bad.

If you're talking about exact colour rendering (Pantones etc), there's no
way to get them right, but the PNG format helps a bit because you can store
gamma information (although I'm not sure which browsers will use it, and
anyway most users won't have their browsers set up for it).

I tend to just get the images looking right on a monitor set up for sRGB,
and hope they don't vary too much in the wild.

 

[News]

There is a semi-official 'web safe' palette, but these days pretty much
all
palettes are web safe so I wouldn't bother. Besides, the few computers
that
still reduce the colours won't look all *that* bad.

If you're talking about exact colour rendering (Pantones etc), there's no
way to get them right, but the PNG format helps a bit because you can
store
gamma information (although I'm not sure which browsers will use it, and
anyway most users won't have their browsers set up for it).

I tend to just get the images looking right on a monitor set up for sRGB,
and hope they don't vary too much in the wild.

Thanks

 

[News]

Maybe back it the days of 8-bit video cards, however you have no control
over whether your visitors have their monitor's adjusted properly and
color calibrated.

Thanks

 

[cwdjrxyz]

Is it true that there is a limited number of colors that can be rendered on
the internet?

If this is true, where can I go to learn about it?

Will the colors in an image be altered if the colors are not the correct
hue?

At one time only a limited number of colors could be rendered the same
by the then current, but now ancient, browsers. However all of the most
popular recent browsers are capable of rendering millions of colors
properly. One exception is for a few of the old WebTV(now MSNTV) boxes,
with their bowser browsers, still in use, which have only 8-bit color
depth, but the newer MSNTV boxes use a watered down IE6 browser and
render color the same as a normal IE6 browser.

Just because the browser is capable of millions of colors does not mean
that all image formats can use all of these. For example, the gif
allows only a very limited range of colors, making it best for
animations, poster-like images, etc. However the jpg and png can handle
a full color range. Thus for accurate colors for photographs, a gif
should be avoided.

 

[News]

At one time only a limited number of colors could be rendered the same
by the then current, but now ancient, browsers. However all of the most
popular recent browsers are capable of rendering millions of colors
properly. One exception is for a few of the old WebTV(now MSNTV) boxes,
with their bowser browsers, still in use, which have only 8-bit color
depth, but the newer MSNTV boxes use a watered down IE6 browser and
render color the same as a normal IE6 browser.

Just because the browser is capable of millions of colors does not mean
that all image formats can use all of these. For example, the gif
allows only a very limited range of colors, making it best for
animations, poster-like images, etc. However the jpg and png can handle
a full color range. Thus for accurate colors for photographs, a gif
should be avoided.

Grief there is so much to learn, thanks for this information.

 

[Neredbojias]

To further the education of mankind, "News"

Is it true that there is a limited number of colors that can be
rendered on the internet?

Yep. I think it's around 16,777,216.

If this is true, where can I go to learn about it?

A search engine like Google. I dunno, maybe the string "color depth" might
work.

Will the colors in an image be altered if the colors are not the
correct hue?

If a part of the system is incapable of displaying the image's color
spectrum, yes.

 

[Toby Inkster]

If you're talking about exact colour rendering (Pantones etc), there's no
way to get them right, but the PNG format helps a bit because you can store
gamma information (although I'm not sure which browsers will use it, and
anyway most users won't have their browsers set up for it).

Gamma is supported by any vaguely recent Gecko browser, Opera and IE/mac
(as well as a handful of other minor browsers -- Amaya and Dillo spring to
mind).

More important is what's missing though: IE/win, Safari and Konqueror.

 

[Andy Dingley]

Thus for accurate colors for photographs, a gif
should be avoided.

GIF should be avoided for "overall accurate rendering". However if you
want to match a logo and a CSS colour so that one bleeds cleanly into
another, then use a pallette-based image format like GIF or PNG,
definitely not JPG. JPG offers lots of colours with good shading, but
it's lossy compression so they're all a little approximate. If it's a
question of matching solid colour blocks of one shade, then JPG is a bad
choice.

 

[Nik Coughlin]

GIF should be avoided for "overall accurate rendering". However if you
want to match a logo and a CSS colour so that one bleeds cleanly into
another, then use a pallette-based image format like GIF or PNG,
definitely not JPG. JPG offers lots of colours with good shading, but
it's lossy compression so they're all a little approximate. If it's a
question of matching solid colour blocks of one shade, then JPG is a
bad choice.

In fact, if you need to colour match an image with a CSS colour, use GIF
whenever possible over PNG, as the gamma correction in PNG will cause a
mismatch in some browsers:

 

[Nik Coughlin]

In fact, if you need to colour match an image with a CSS colour, use
GIF whenever possible over PNG, as the gamma correction in PNG will
cause a mismatch in some browsers:

Whoops:
http://hsivonen.iki.fi/png-gamma/

 

[cwdjrxyz]

Gamma is supported by any vaguely recent Gecko browser, Opera and IE/mac
(as well as a handful of other minor browsers -- Amaya and Dillo spring to
mind).

More important is what's missing though: IE/win, Safari and Konqueror.

We have been talking about color rendition with the assumption that the
monitor or TV screen is capable of and set for perfect color rendition.
However I have seen cases when the adjustments of the monitor are very
far off. You become used to poor color rendition, if not too extreme,
very easily. To accurately set the monitor you need a test DVD such as
is used to set up home theatre. It not only allows adjustment of the
images, but also the audio for multi-channel set ups. The very best
adjustment may require instruments, but many test DVDs come with
filters for your eyes and other devices to make very good adjustment
possible.

Lacking a test DVD, the color bars and test screens broadcast by TV
stations can be helpful, but they are seldom on anymore where I live,
and they will not help for your computer unless you have a TV tuner in
the computer.

I have an old monitor adjustment page at
http://www.cwdjr.net/tool/a_color_bars.html that still gets a few hits
despite the age of it. I strongly suggest using the mentioned DVD home
theatre set up test discs, but the color bars and other tests on my
page are better than nothing.

Not all monitors or TVs have all of the adjustments needed for best
reproduction on the screen. Home theatre projectors tend to have more
adjustments than most other formats. However, on smaller TVs, there
often are many additional adjustments on a hidden menu. The key to
bringing up this menu usually is not provided to buyers of the TV,
because using some of the hidden adjustments require instruments, and
one can easly greatly distort the image or even damage the TV. My
computer monitor has more adjustments than a typical small TV, but not
as many as most TV projectors. I do not think it has any hidden menus,
but who knows for sure.

 

[News]

To further the education of mankind, "News"


Yep. I think it's around 16,777,216.

Grief is that all, there is no way I will be able to make my site work now.
;-)

A search engine like Google. I dunno, maybe the string "color depth"
might work.

No kidding? I did that and found heaps of sites that said it is STILL valid
and others that said it is obsolete. I am not a caveman and don't think just
because it is painted on the wall it must be true

If a part of the system is incapable of displaying the image's color
spectrum, yes.

Thanks

 

[Neredbojias]

To further the education of mankind, "News"

Grief is that all, there is no way I will be able to make my site work
now. ;-)


No kidding? I did that and found heaps of sites that said it is STILL
valid and others that said it is obsolete. I am not a caveman and
don't think just because it is painted on the wall it must be true

I was a caveman once but they threw me in the hoosegow 'cause my loin cloth
didn't meet community standards.

Anyhow, I suppose everyone has an opinion, but the fact is that "web-safe
colors" is term that is now mostly passe. Most computers, monitors,
browsers, et al can display each one of the 16+ million colors just fine.
Devices that possibly can't, such as those phone-things or whatever,
probably have an algorthm which transduces colors satisfactorily.

 

[Blinky the Shark]

I was a caveman once but they threw me in the hoosegow 'cause my loin
cloth didn't meet community standards.

More loin than cloth, eh?

 

[frederick]

However I have seen cases when the adjustments of the monitor are very
far off. You become used to poor color rendition, if not too extreme,
very easily.

I can vouch for that, being partially colour-blind!

Not that I ever particularly wanted to get a job on the railways or as
a fighter pilot, but it would've been nice to have had the option...

 

[frederick]

No kidding? I did that and found heaps of sites that said it is STILL valid
and others that said it is obsolete. I am not a caveman and don't think just
because it is painted on the wall it must be true

A useful attitude to have, particularly when using Google to find
discussions of best web practice. It's amazing how long some pages
stay up!

Regarding "web-safe colours":
It's mainly used to refer to a palette of 216 colours that were
rendered identically on both Microsoft Windows and Apple systems, and
in both Netscape Navigator (remember that?!) and Internet Explorer.
This was back when many or most people had lower-resolution monitors
with a lesser colour depth, of course; not to mention the annoying
practice amongst OEMs of selling customers monitors capable of a higher
resolution but which left the factory set at a lower one.

Anyhoo, since even mobile 'phones can usually handle millions of
colours, it's a historical curiosity in most cases. Gamma and whatever
else might mean that the millions of colours that I see aren't exactly
the same as the ones that you do, but unless you're developing a
website for a paint manufacturer it's largely going to be a technical
irrelevancy. IMHO, YMMV, etc.

 

[Neredbojias]

More loin than cloth, eh?

Well, to be frank, it wasn't the loin that was the problem.

 

[Blinky the Shark]

To further the education of mankind, Blinky the Shark


Well, to be frank, it wasn't the loin that was the problem.

No GIF! No GIF!